1. Field of the Invention
The present invention relates to a method for generating a control signal. More particularly, the present invention relates to a method for generating free run control signals.
2. Description of Related Art
Driving signals of a liquid crystal display (LCD) panel mainly includes a data signal provided by a source driver and a scan signal provided by a gate driver. The data signal mainly provides a voltage signal corresponding to gray level of each pixel. The scan signal is used for controlling a switch signal input by each row of pixel voltages, and the scan signal is a progressive scan signal. In the LCD, a timing controller (TCON) has to be applied to output a control signal S to drive the source driver and the gate driver located on a panel module, so as to display a correct image. The timing controller must generate the required control signal S according to a data enable signal DE of an input image signal, and when variation of the data enable signal DE is ceased (i.e. when the data enable signal is discontinuous) generation of the control signal is also ceased because the data enable signal DE of the input image signal is not a continuous signal.
FIG. 1 is a schematic diagram illustrating a conventional technique of generating a control signal. Referring to FIG. 1, when the data enable signal DE continuously outputs square waves, the control signal S also generates the corresponding square wave along with a transition variation of the data enable signal DE. When the data enable signal DE is maintained to a low level and is no longer varied, the control signal S can only be maintained to a fixed value, and cannot generate the square wave. Therefore, driving techniques for black frame insertion and multi-domain wide viewing angle panel, etc. cannot be applied.